Okay but in many mythos there is this "body parts have mysterious properties" and have gods growing things with their tears and etc. How about Maid of Void with blood that causes blindness when ingested in exchange for forbidden magics. Or tears of heir of life that cause one's body to grow as tough as steel. Hair of Seer of Light that if vowen into string, will lead to the safest path. Or saliva of Bard of Mind that causes one to go mad.
As much as I like something like this in comparison to old myths and such, please let’s slow down this train of thought before we start considering cannibalizing other God Tier friends in exchange for forbidden God Tier Powers.